1. Field of the Invention
The present invention relates to a multiradiation generation apparatus, which is applicable to, for example, nondestructive X-ray imaging used in the fields of medical equipment and industrial equipment, and to a radiation imaging system using the multiradiation generation apparatus.
2. Description of the Related Art
In recent years, in the field of radiation imaging such as mammography, tomosynthesis imaging has been performed as a technique for obtaining information on the depth direction of an object. In tomosynthesis imaging, an object is irradiated with radiation from a plurality of angles to capture a plurality of images. The obtained images are reconstructed to obtain a cross-sectional image.
Normally, in tomosynthesis imaging, an operator performs imaging by irradiating an object with radiation while moving radiation tubes at an angle within a predetermined angle range (approximately ±7.5° to ±25°) with respect to the object.
U.S. Pat. No. 8,094,773 discusses a three-dimensional X-ray image generation device. By using a plurality of X-ray sources and sequentially irradiating an object with the X rays from a plurality of angles, this device performs tomosynthesis imaging while maintaining the X-ray sources in a fixed state. In addition, there is discussed a device including non-tomosynthesis imaging X-ray sources outside a tomosynthesis imaging path, in addition to tomosynthesis imaging X-ray sources.
The apparatus that involves the movement of the radiation tubes during imaging has problems. For example, artifacts are formed on images. In addition, since time is required for the mechanical movement, imaging time is prolonged. In addition, movement of the radiation tubes could give a subject a sense of fear.
In clinical practice, there are cases in which both tomosynthesis images and conventional two-dimensional (2D) images (non-tomosynthesis images) are used. These 2D images are advantageous since the 2D images can provide higher spatial resolution than that of tomosynthesis images and medical professionals can make use of years of knowledge. Thus, it is effective to use tomosynthesis images for specifically observing a portion that seems suspicious on 2D images.
However, if tomosynthesis imaging radiation sources and non-tomosynthesis imaging radiation sources are separately provided, the configurations of the apparatuses are made complex, thereby increasing manufacturing costs of the apparatuses. In addition, the tomosynthesis images and non-tomosynthesis images need to be appropriately associated with each other. Thus, the positional relationship among the tomosynthesis imaging radiation sources and the non-tomosynthesis imaging radiation sources needs to be optimized, which is a layout constraint.